The point is that you want to take it really easy when attempting to "get into the game" that is cardio. If you've been out of the game for quite awhile your body is going to repel any attempt at cardio, walking included. It's possible that even a simple walk around the block will leave you sore the next day if you are extremely out of shape. But that's okay! If you take things slow and easy all the while progressing it will get much better and much easier.
You could start out by just walking around your neighborhood with no incline twice a week. Do this for a few weeks and your endurance will become stronger. After you feel that this is a breeze kick up the length walked or walk in an area that provides an incline if you are feeling brave. Do this for a few weeks and eventually work your way up to a light jog. You see, it's all about progress while taking into account your current endurance and comfort level. The time it takes to advance in cardio difficulty will change from person to person and depends on various variables.
Furthermore, not everyone will be interested in becoming a regular jogger. Walking is just fine for millions of people everyday so why shouldn't it work for someone else looking to stay healthy? It isn't as good for you as jogging is but it is still a very healthy activity and will certainly kick anyone into decent shape with enough time and persistence. The choice is yours and anyway you take it it's good for you.